chore: add `exports` field to package.json

[hslee2008]

1863

[metonym]

Thanks for this. In my testing, subpaths for css and src need to included as well.

Otherwise, these imports would fail when Vite attempts to prebundle the library:

import "carbon-components-svelte/css/all.css";
import Button from "carbon-components-svelte/src/Button/Button.svelte";

[metonym]

Fixed in v0.82.5